EnerVest Ltd. appointed Ken Mariani as company president, the company said Jan. 15. Mariani will focus on acquisitions, planning and analysis, the company added. Additionally, EnerVest appointed Stephen McDaniel president and CEO of subsidiary EnerVest Operating Co., and Jud Walker as executive vice president and chief operating officer of the same, the company added.

"Ken's leadership skills have enhanced our operations and provided strong direction for our employees," said company founder John Walker. He added, "we are blessed to have a strong management team, and I look forward to working closely with Ken in his new role."

Mariani joined EnerVest Ltd. in 2000 and most recently was its executive vice president, the company said. He was also EnerVest Operating Co.’s president and CEO, the company added.

Prior to joining EnerVest, he was vice president, operations for Energy Corporation of America, and oversaw engineering, land, geology and production operations.

Houston-based EnerVest Ltd. acquires, develops and operates more than 23,000 oil and gas wells in 15 states on behalf of its institutional investors.